Grinder roll



Dec. 15, 1925.

0. ARA M- GRINDER ROLL 5 Filed April 4, 19 22 ff afia? WWQW 4 ATTORNEYZZZ v AM); dig/45hr WITNESS S' Patented Dec. 15, 1925.

UNITED STATES PATENT OFFICE.

GRINDER ROLL.

Application filed April 4, 1922. Serial No. 549,492.

To all whom it may concern:

Be it known that I, OTTO ARAM, a citizen of the United States, and aresident of Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a new and useful Improvement in GrinderRolls, of Which the following is a specification.

My invention relates to grinder rolls, particularly to rolls of thecharacter employed in removing clinker and ash from mechanicallyoperated furnaces, and it has for an object to provide, in an apparatusof the character designated, a built-up structurewhich shall be capableof assembly in varying lengths to accommodate furnaces of differentwidths, and in which the torsional stresses imposed upon the grinderroll shall be carried by overlapping castings rigidly secured one toanother and carried by a single shaft. Anotherobject of my invention isto provide a grinder roll which shall have a continuous cutting actionduring rotation thereof, which cuttingaction shall be produced by twospirally arranged series of cutters disposed diametrically opposite toeach other and extending the length of the roll. I

It is a still further object of my invention to provide in a grinderroll of this character an interchangeable tooth structure which may bereadily replaceable and which shall exert a cutting action in eitherdirection of rotation of the roll.

These, and other objects which are made more manifest in the furtherdescription of my invention, may be attained in the a paratushereinafter described and illustrated in the accompanying drawings, inwhich Fig. 1 is a view in elevation showing the assembled roll, theteeth being omittedin order to show more clearly the arrangement andmode of fastening of the semi-cylindrical castings; Fig. 2 is a view insection taken on line II-II of Fig. 1; Fig. 3 is a similar sectionalView taken on line IIIIII of Fig. 1; Fig. 4 is a longitudinal sectionalview of one of the hollow semi-cylindrical castings; Fig. 5 is a View inend elevation of the casting illustrated in Fig. 4; Fig. 6 is anenlarged detailed View in side elevation of one of the interchangeableteeth; and Fig. 7 is an end view of the tooth illustrated in Fig. 7.

High duty furnaces of central power stations are usually of considerablewidth and the grinder rolls therefor, commonly located at the bottom ofthe refuse pit, are of a length corresponding to the width of thefurnace. The power for rotating grinder rolls is ordinarily applied atone end of the roll, or in extremely wide furnaces where two alignedrolls are employed the'power is applied at the outer end of each roll, aconstruction which imposes severe torsional stresses upon the shaftsupporting the roll. The present invention contemplates the absorptionof these torsional stresses by employing sectional, semi-cylindricalhollow castings bolted together lation around an axially disposed shaftto form a light and rigid built-up structure.

The grinder roll described in the present application, when designed foruse in connection with a standard underfeed stoker, comprises anassembly of two distinct 1101-. low, semi-cylindrical castings. In orderthat from these castings rolls of any desired length, as for example,for a 5, 7 or 9 retort stoker, may be readily assembled, it ispreferable to construct one of the said castings equal in length to thewidth of a retort and the other casting twice that length.

The castings are suitably cored for the reception of interchangeableteeth, the tooth openin 's being symmetrically disposed about t ecylindricalsurfaces of the castings in such manner as to produce adouble helical series of teeth for any assembly of sectional castin s.

All teeth for the roll are removable and interchangeable andconsequently may be cast from a single pattern. Each tooth is designedto abut at its in er square end against a supporting shaft and to engagethe cylindrical shell of the roll of castings by means of a shoulder. Noother securing means for the teeth is necessary since each tooth is heldsecurely in place by bolting together the castings in their assembledrelation.

Referring to the drawings for a more detailed description of myinvention, in Fig. l I show at 10 an assembled roll composed ofshort-hollow, semi-cylindrical castings 11, and long hollow cylindricalcastings 12. The longer castings 12 are pre ferably twice the length ofthe castings ll so that by combination of these castings, rolls ofvarying lengths to meet the reln overlapping requirements of anyinstallation may be constructed. Each of the castings 11, 12 has closedend portions 13, provided with right triangular notches 14, adapted toengage a square shaft 15 when in an assembled position. Cored holes 16are provided in the. end portions of the short castings 11 and in theend and intermediate portions of the castings 12, the holes 16 beingsuitably disposed for the reception of bolts 17 by means of which thecastings are held securely to each other and to the square shaft. Eachcasting is further provided with a plurality of cored radial openings 19for the reception of the cutting teeth 20, the arrangement of theseopenings being such that upon a proper assembly of any number ofsections, a double series of diametrically opposed teeth 20 may belocated therein.

Each tooth 20 consists of a base portion 21 having a beveled end face22, which engages a side of the square shaft, and a cutting or bladeportion 23 which protrudes beyond the periphery of the cylindrical roll.Between these portions, a tapered portion 2a, which engages acooperating shoulder 25 in the opening 19, serves to hold the. tooth inposition against the shaft 14. The outer end of the tooth is preferablyslightly concave, as at 27, to provide a cutting edge in eitherdirection of the grinder roll.

The assembly and the operation of my improved grinder roll is evidentfrom the above description. In brief, when it is desired to equip astoker of any given capacity, the requisite number of long and shortsemi-cylindrical castings are selected and the teeth 20 slipped into theseveral apertures 19, in such manner that the beveled faces will engagethe sides of the square shaft 15. The castings are then placed about theshaft and bolted to each other so that the sections form a rigidintegral cylindrical roll in which the teeth are securely held becauseof their engagement between the shaft and the shoulders 26 of theopenings in the castings. The assembled structure is then ready forinstallation.

My novel construction of grinder roll possesses many advantages oversimilar structures commonly employed. The roll hereinbefore described isconstructed from four different stock parts, namely, standard long andshort semi-cylindrical castings, standard teeth, and a square shaft cutto the proper length, from which standard parts grinder rolls of anydesired length may be assembled. There is thus obtained a materialeconomy in the cost of construction and maintenance of the grinder rolldue to the reduction in labor required to make the few standard partsneeded for all sizes of equipment, the fewer parts necessary to becarried in stock both by the manufacturer and the user of the machineand the readiness with which any part or parts may be replaced when wornor broken. These advantages are obtained without in any way sacrificingthe strength or effectiveness of the roll. Rather has it been found intests conducted under actual operating conditions that the severalcastings assembled as herein described give the roll the rigidity of anintegral structure and relieves the shaft of the torsional stressesnormally carried thereby.

\Vhile I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications, without departing from thespirit thereof, and I desire therefore, that only such limitations shallbe placed thereupon as are imposed by the prior art or as arespecifically set forth in the appended claims.

lVhat I claim is:

1. In the art of constructing grinder rolls for stoker furnaces in whichthe rolls comprise a cylindrical member provided with projecting teeth,the method of constructing such rolls of varying lengths which consistsin preparing a plurality of semicylindrical castings of a unit length,preparing a plurality similar castings of twice the unit length, allsaid castings having identically disposed openings for the reception ofteeth and bolts, preparing a plurality of teeth of a single size andpattern, then assembling the teeth in a number of castings requisite toform when assembled a roll of the length required and securing thesemi-cylindrical castings to each other in overlapping relation about asquare shaft with the teeth abutting said shaft cut to a requisitelength to form the desired toothed cylindrical grinder roll.

2. A grinder roll for a stoker furnace comprising a square shaft,semi-cylindrical castings secured together in overlapping relation toform a cylindrical grinder roll, said castings being provided withopenings and teeth extending through said openings, one end of the teethabutting the sides of the shaft.

3. A grinder roll for a stoker furnace comprising a polygonal shaft,teeth extending outwardly from the shaft, one end of each tooth abuttingthe shaft and one edge of said end lying substantially along a corner ofthe shaft, and means for holding the teeth in engagement with the shaft.

4. A grinder roll for a stoker furnace comprising a square shaft, andsemi-cylindrical castings secured together to form a cylindrical grinderroll and having notched portions to embrace said shaft, and cuttingteeth carried by the castings, and abutting said shaft.

5. A grinder roll for a stoker furnace comprising a square shaft,semi-cylindrical castings secured together to form a cylindrical grinderroll and having notched portions to embrace said shaft, and teethcarried by the castings and so disposed therein in abutting relation tosaid shaft as to form two diametrically opposite helical series or rowsof cutting teeth.

6. A grinder roll for a stoker furnace comprising semi-cylindricalcastings secured together to form a cylindrical grinder roll, a squareshaft disposed axially of and supporting the assembled roll, saidcastings having openings for the reception of cut-- ting teeth, cuttingteeth projecting through said openings and held rigidly therein byengagement with the shaft and the castings.

A grinder roll for a stoker furnace comprising hollow semi-cylindricalcastings secured together to form a cylindrical grinder roll, a squareshaft disposed axially of and supporting the assembled roll, saidcastings having openings for the reception of cutting teeth,interchangeable and removable cutting teeth projecting through saidopenings, said teeth being held rigidly therein by engagement With theshaft and the castings.

8. A grinder roll for a stoker furnace, comprising a square shaft,semi-cylindrical castings of unit length, a plurality of semicylindricalcastings of twice the unit length, said castings being secured togetherin overlapping relation to form a rigid grinder roll and having notchedend portions to embrace said shaft. a

9. A grinder roll for a stoker furnace comprising hollow,semi-cylindrical castings secured together to form a cylindrical grinderroll, a square shaft disposed axially of and supporting the assembledroll, said casting having openings for the reception of cutting teeth,interchangeable and removable cutting'teeth projecting through saidopenings, the base portion of each of said teeth being beveled to fitagainst the sides of the square shaft.

10. A grinder roll for a stoker furnace comprising hollow,semi-cylindrical castings secured together to form a cylindrical grinderroll, a square shaft disposed axially of and supporting the assembledroll, said castings having openings for the reception of cutting teeth,interchangeable and removable cutting teeth projecting through saidopenings, each of said teeth being provided with an intermediateshoulder to engage a cooperating shoulder in the said opening, and abeveled inner face to fit against a side of the square shaft, wherebythe teeth are held rigid with respect to the assembled roll.

g 11. A grinder roll for a stoker furnace comprising hollow,semi-cylindrical castings secured together to form a semi-cylindricalgrinder roll, a square shaft disposed axially of and embraced by eachcasting of the assembled roll, said castings having openings for thereception of cutting teeth, cutting teeth projecting through saidopenings, and said openings being so disposed as to carry twodiametrically opposite helical series or rows of cutting teeth, saidteeth abutting said shaft.

12. A grinder roll for a stoker furnace comprising a plurality ofhollow, semi-cylindrical castings, some of the said castings being twicethe length of other castings, said castings having radially coredopenings for the reception of cutting teeth, cutting teeth disposed insaid openings, and a shaft, the arrangement of the above parts beingsuch that when the semi-cylindrical castings are secured together aboutthe shaft the teeth are held rigid with respect to the as sembled rollby engagement with the shaft and the castings.

13. In a clinker grinder roll for a stoker, the combination with a shaftwhose cross section is a polygon of an even number of sides, of aplurality of pairs of teeth, the teeth of each pair engaging oppositesides of the shaft and having their axes parallel and lying in a planenormal to the axis of the shaft.

In testimony whereof, I have hereunto subscribed my name this 29th dayof March, 1922.

OTTO ARAM.

